Structural coupling in oxide perovskite heterostructures provides a route for engineering electronic properties. Additionally, alternative crystal orientations, such as the [111] direction, offer an additional degree of freedom for tuning these properties. These concepts merge in the experimental realization of a [111]-oriented bilayer, which, assuming a cubic crystal structure, is theoretically predicted to exhibit a Chern insulating phase due to the $C_{3v}$ symmetry. However, deviations from the cubic crystal structure in the form of crystal distortions, such as the Jahn-Teller distortions, break the $C_{3v}$ symmetry and suppress the Chern insulating phase. Here, we investigate the structural properties of ${\mathrm{LaMnO}}_3$ bilayer heterostructures, and thin films on ${\mathrm{LaAlO}}_3, {\mathrm{SrTiO}}_3$, and ${\mathrm{DyScO}}_3$ [111]-oriented substrates deposited by pulsed laser deposition. Scanning transmission electron microscopy confirms the bilayer structure and reveals the presence of distortions from the cubic symmetry, indirectly suggesting the presence of Jahn-Teller distortions, on ${\mathrm{LaAlO}}_3$ and ${\mathrm{DyScO}}_3$. On ${\mathrm{SrTiO}}_3$ the observed distortions are significantly suppressed. We quantify these distortions and demonstrate that their magnitude varies with strain and substrate coupling.

Indium tin oxide (Sn-doped ${\mathrm{In}}_2{\mathrm{O}}_3$; ITO) is a well-studied transparent conductor where doping can be used to stabilize a superconducting state. In this work, we use a combination of thin film deposition of ITO and solution-phase chemistry using $n\text{-BuLi}$ (${\mathrm{C}}_4{\mathrm{H}}_9\mathrm{Li}$) to realize superconductivity in Li-doped ITO. Solution-phase intercalation is commonly employed for bulk, polycrystalline materials but has rarely been applied to thin films. Using x-ray diffraction, atomic force microscopy, electronic transport, and optical transmission measurements, we characterize the optical transparency and superconductivity of lithium intercalated ITO thin films. After 72 hours of lithium intercalation, we find a critical temperature, $T_{\text{c}}$, of 0.49 K and an optical transparency of at least $73\%$ in the visible optical range—all while maintaining crystallinity and nanometer surface roughness.

Magnetic skyrmions are nanometer-sized whirling spin textures in the magnetic material, which have the potential to revolutionize the field of spintronics. This study explores the influence of pressure on the structural properties of the PtMnGa hexagonal system, recognized for hosting Néel skyrmions. By employing pressure-dependent synchrotron x-ray powder diffraction (SXRPD), we reveal an isostructural phase transition in this system at approximately 6 GPa. The isostructural transition is evidenced by a deviation of the lattice parameter from the linear dependence, change of trend in the in-plane to out-of-plane lattice parameter ratio, and a description of the pressure-unit cell volume data by two distinct second-order Birch-Muraghan equation of states. The PtMnGa system, however, exhibits reversible structural behavior when pressure is released. Analysis of combined pressure and temperature-dependent SXRPD data provides indirect evidence that the application of moderate pressure (0.8–1.09 GPa) shifts the thermodynamically stable skyrmion regime near to room temperature in the Néel skyrmion-host PtMnGa system. Theoretical calculations on band structure, magnetic moment, and density of states (DOS) under pressure further corroborate the experimental findings, offering a comprehensive understanding of the material's response to pressure changes. The combination of experimental findings and theoretical calculations demonstrates the potential for engineering materials supporting stable skyrmions even at elevated temperatures and nominal pressures, which can be attained in the materials using chemical substitution or epitaxial thin films by strain controlling of the substrate-film lattice parameter mismatch.

We present a lattice model for polymer solutions, explicitly incorporating interactions with a bath of solvent and cosolvent molecules. By exploiting the well-known analogy between polymer systems and the $O\left(n\right)$-vector spin model in the limit $n\to 0$, we derive an exact field-theoretic expression for the partition function of the system. The latter is then evaluated at the saddle point, providing a mean-field estimate of the free energy. The resulting expression, which conforms to the Flory-Huggins type, is then used to analyze the system's stability with respect to phase separation, complemented by a numerical approach based on convex hull evaluation. We demonstrate that this simple lattice model can effectively explain the behavior of a variety of seemingly unrelated polymer systems, which have been predominantly investigated in the past only through numerical simulations. This includes both single-chain and multichain solutions. Our findings emphasize the fundamental, mutually competing roles of solvent and cosolvent in polymer systems.

Kagome metals are a unique class of quantum materials characterized by their distinct atomic lattice arrangement, featuring interlocking triangles and expansive hexagonal voids. These lattice structures impart exotic properties, including superconductivity, interaction-driven topological many-body phenomena, and magnetism, among others. The kagome metal ${\mathrm{CsM}}_3{\mathrm{Te}}_5$ (where M = Ti, Zr, or Hf) exhibits both superconductivity and nontrivial topological electronic properties, offering a promising platform for exploring topological superconductivity. This study employs first-principles density functional theory calculations to systematically analyze the elastic, mechanical, vibrational, thermodynamic, and electronic properties of ${\mathrm{CsM}}_3{\mathrm{Te}}_5$ (M = Ti, Zr, Hf). Our calculations reveal that the studied compounds—${\mathrm{CsTi}}_3{\mathrm{Te}}_5$, ${\mathrm{CsZr}}_3{\mathrm{Te}}_5$, and ${\mathrm{CsHf}}_3{\mathrm{Te}}_5$—are ductile metals with elastic properties akin to the hexagonal Bi and Sb, with average elastic constants, including a bulk modulus of 27 GPa, a shear modulus of 11 GPa, and Young's modulus of 29 GPa. We observe peculiar dispersionless, flat, phonon branches in the vibrational spectra of these metals. Additionally, we thoroughly analyze the symmetries of the zone-center phonon eigenvectors and predict vibrational fingerprints of the Raman- and infrared-active phonon modes. The analysis of thermodynamic properties reveals the Einstein temperature for ${\mathrm{CsTi}}_3{\mathrm{Te}}_5$, ${\mathrm{CsZr}}_3{\mathrm{Te}}_5$, and ${\mathrm{CsHf}}_3{\mathrm{Te}}_5$ to be 66, 54, and 53 K, respectively. Our orbital-decomposed electronic structure calculations reveal significant in-plane steric interactions and multiple Dirac band crossings near the Fermi level. We further investigate the role of spin-orbit coupling effect on the studied properties. This theoretical investigation sheds light on the intriguing quantum behavior of kagome metals.

The diverse and intriguing phenomena observed in twisted bilayer systems, such as graphene and transition-metal dichalcogenides, prompted new questions about the emergent effects that they may host. However, the practical challenge of realizing these structures on a scale large enough for spectroscopic investigation, remains a significant hurdle, resulting in a scarcity of direct measurements of the electronic band structure of twisted transition metal dichalcogenide bilayers. Here, we present a systematic nanoscale angle-resolved photoemission spectroscopy investigation of bulk, single-layer, and twisted bilayer $\mathrm{W}{\mathrm{S}}_2$ with a small twist angle of $4.4^{\circ }$. The experimental results are compared with theoretical calculations based on density functional theory along the high-symmetry directions $\overline{\mathrm{\Gamma }}\text{−}\overline{\mathrm{K}}$ and $\overline{\mathrm{\Gamma }}\text{−}\overline{\mathrm{M}}$. Surprisingly, the electronic band structure measurements suggest a structural relaxation occurring at $4.4^{\circ }$ twist angle and the formation of large, untwisted bilayer regions replacing most of the twisted area.

It is well established that theoretical prediction of the stable crystal structure of a compound is essential to calculating its electronic properties. When the theoretically predicted structure conflicts with the experimentally assessed structure, it is natural to assume that theory is wrong. An example is $\delta \text{−}\mathrm{B}{\mathrm{i}}_2{\mathrm{O}}_3$—an important functional material associated with its record oxygen transport. The standard first step in theoretical structure prediction involves calculation of the “Convex Hull” diagram C (x, S, $\mathrm{T}=0$) contrasting the zero temperature energies of all currently imaginable competing phases at different compositions x and structures S, retaining the phases that persist with respect to decomposition into other constituents. Proximity of the energy of a structure to the Convex Hull indicates its expected theoretical stability. Surprisingly, the documented nominal fluorite crystal structure of $\delta \text{−}\mathrm{B}{\mathrm{i}}_2{\mathrm{O}}_3$—refined from X-ray diffraction (XRD)—is nowhere near the bottom of the Convex Hull calculated with state-of-the-art density functional theory (DFT). This apparent failure of theory comes with additional puzzles. First, using the measured nominal structure as input to DFT band theory predicts the $\delta$ phase to be a zero-gap metal, in stark contrast with its known insulating properties. Second, phonon calculations indicate that the nominal fluorite structure is not even dynamically stable, exhibiting imaginary phonons. Third, extending the Convex Hull concept to finite temperatures C(x, S, T) via “Compressive Sensing” machine learning reveals that the documented nominal crystal structure has high free energy above the Convex Hull. Here, we study theoretically the possibility that the refined structure for the δ phase was, in fact, an effective average “virtual structure,” not to be taken literally. To test this, we retain the global macroscopic crystallographic cell symmetry but increase the unit cell to a supercell, allowing local atomic positions to deviate from the artificially imposed average, seeking minimum calculated total energy. This reveals a macroscopically cubic but locally noncubic distribution of low symmetry local motifs. Importantly, this "polymorphous network" distribution has a lower total energy, it correctly predicts an insulating phase and agrees with the measured pair distribution function much better than the literature average structure. It appears that experimentally determined high-symmetry virtual average structure is not realistic.

Chirality in tellurium arises from a Peierls distortion driven by strong electron-phonon coupling, making this material a unique candidate for observing a light-induced topological phase transition. Using time- and angle-resolved photoelectron spectroscopy (trARPES), we reveal that, upon near-infrared photoexcitation, the Peierls gap is modulated by displacively excited coherent phonons with ${\mathrm{A}}_{1\mathrm{g}}$ symmetry as well as chiral-symmetry-breaking ${\mathrm{E}}_{\mathrm{LO}}^{\prime }$ modes. By comparison with state-of-the-art $\mathrm{TDDFT}+\mathrm{U}$ calculations, we reveal the microscopic origin of the in-phase oscillations of band edges, owing to phonon-induced modulation of the effective Hubbard $U$ term.

Grain boundaries (GBs) govern critical properties of polycrystalline materials. Although significant advancements have been made in characterizing minimum energy and ordered GBs, real GBs are seldom found in such well-defined states. This diversity of atomic arrangements in metastable states makes it challenging to establish structure-property relationships with physical insights. To address this challenge, we use data-driven methods to explore these relationships and examine the underlying physics. In this study, we utilize a large atomistic database $(\sim 5000)$ of minimum energy and metastable states of symmetric-tilt copper GBs, combined with physically motivated local atomic environment (LAE) descriptors [strain functional descriptors (SFDs)], to predict GB properties and gain physical insights. Our regression models exhibit robust predictive capabilities using only 19 descriptors, generalizing to atomic environments in nanocrystals. A significant highlight of our work is the integration of an unsupervised method with SFDs to elucidate LAEs at GBs and their role in determining properties. The model, trained on these minimum energy and metastable GBs using SFDs, predicts the properties of unseen nanocrystals with good accuracy. Our research underscores the role of a physics-based representation of LAEs and the efficacy of data-driven methods in establishing GB structure-property relationships.

It was shown by Prodan in 2009 that both magnetic and nonmagnetic two-dimensional insulators can support quantized spin-Chern number in the absence of spin-rotation symmetry as a bulk topological invariant, which is robust against impurity effects. Recent studies on higher-order and fragile topological insulators further demonstrate that the spin-Chern number can exist without gapless edge states. Therefore, the presence of generalized quantum spin-Hall states in real materials can be difficult to identify using only symmetry-based indicators and Wannier obstruction. Such phases require more sophisticated probes of bulk topology. Magnetic flux tube has emerged as one such singular real-space probe that leads to spin-charge separation and allows for a precise diagnosis of the spin-Chern number. In this paper, we develop an automated workflow to scan the database of experimentally relevant, large band-gap, two-dimensional insulators using magnetic flux tubes. The results reveal many material candidates of higher-order topological insulators possessing double spin-Chern number, including the 1H-${MX}_2$ family of transition metal dichalcogenides. Our paper has broad implications for current efforts to employ these materials for new platforms of moiré systems.

The potential contribution to spin-charge conversion from antiferromagnetism in chromium thin films remains a topic of debate. Here we experimentally demonstrate significant spin-to-charge conversion in thermally evaporated chromium thin films via the longitudinal spin Seebeck effect (LSSE) measured with lithographically patterned, self heated metal structures on bulk polycrystalline yttrium-iron-garnet (YIG) substrates, with specific focus on the temperature dependence. We present LSSE between 78 K and 350 K for 10 nm evaporated and sputtered Cr thin films, along with comparison to Pt and Cu films, all deposited at room temperature on a bulk polycrystalline yttrium-iron-garnet (YIG) substrate. Both Cr films show a significant spin-charge conversion via the LSSE, with roughly similar magnitude but quantifiably different temperature dependence. Dimensionless sensitivity measurements, $(T/R)·dR/dT$, of our Cr structures show two distinct peaks centered at roughly 350 K and 200 K for the evaporated Cr film. These two peaks likely indicate the separate Néel temperatures of the incommensurate and commensurate spin density wave antiferromagnetic states coexisting in a strain-driven mixed state for this film. $(T/R)·dR/dT$ for the sputtered film shows clear evidence for only one peak, near the bulk Néel temperature of $\sim 300\mathrm{K}$. Comparison of the normalized spin conversion efficiency for evaporated Cr, sputtered Cr, and literature values for sputtered Cr highlights the potential role of this strained mixed spin density wave state for spin-charge conversion. The temperature evolution of the two sputtered films agrees at all measured temperatures, and with the evaporated film above 200 K. Below 200 K there is a significant enhancement to the LSSE voltage for the evaporated film as compared to the sputtered films. This suggests that spin-charge conversion in our evaporated Cr thin film is affected by the modified spin-density wave antiferromagnetic state, which is driven by a combination of finite-size effects and strain.

This work studies the correlation between noncollinear spin orientation and lattice distortion in $\mathit{XY}$-like spin-glass (SG) $\mathrm{N}{\mathrm{i}}_{0.4}\mathrm{M}{\mathrm{n}}_{0.6}\mathrm{Ti}{\mathrm{O}}_3$ (NMTO) using neutron diffraction and synchrotron-radiation-based spectroscopic techniques such as resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy, and x-ray magnetic circular dichroism (XMCD). The neutron study reveals a shorter spin-spin correlation length along the $\mathit{c}$ axis than in the $\mathit{XY}$-plane, which is typical of $\mathit{XY}$-like SG. It also reveals that the $\mathrm{NiTi}{\mathrm{O}}_3$ matrix dominates the shaping of the low-temperature complex magnetic structure of NMTO. A local lattice distortion in the form of a large increase in the nearest-neighbor Ni-O bond length along the $\mathit{c}$ axis was observed from temperature-dependent extended x-ray absorption fine-structure measurements close to the SG transition temperature, $T_{\mathrm{SG}}$. The Ni $L_3$-edge RIXS spectra at around $T_{\mathrm{SG}}$ indicate a possible magnon excitation with various $d\text{−}d$ interactions and charge-transfer excitation. The Ni $L_{3,2}$-edge XMCD measurement shows ferromagnetic-/ferrimagneticlike behavior at the temperature near $T_{\mathrm{SG}}$, closely matching the opening of hysteresis curves that are recorded below $T_{\mathrm{SG}}$. These findings compellingly demonstrate that at low temperature, $\mathrm{N}{\mathrm{i}}^{2+}$ ions in the $\mathit{XY}$-plane of NMTO exhibit a noncollinear spin alignment, that facilitates Dzyaloshinskii-Moriya-type exchange interactions, elucidating the complex spin dynamics of this SG system.

We present the development and applications of a quadratic spectral neighbor analysis potential (q-SNAP) for ferromagnetic cobalt. Trained on density functional theory calculations using the Perdew-Burke-Ernzerhof (DFT-PBE) functional, this machine-learned potential enables simulations of large systems over extended time scales across a wide range of temperatures and pressures at near DFT accuracy. It is validated by closely reproducing the phonon dispersions of hexagonal close-packed (hcp) and face-centered cubic (fcc) Co, surface energies, and the relative stability of nanoparticles of various shapes. An important feature of this potential is its numerical stability in long molecular dynamics simulations. This robustness is exploited to compute the heat capacity of nanoparticles containing up to 9201 atoms, showing convergence to less than 2 $\mathrm{J}{\mathrm{K}}^{-1}{\mathrm{mol}}^{-1}$ after 100 ns. Computations of the melting temperature of nanoparticles as a function of their size revealed a convergence to the bulk limit in excellent agreement with the experimental value. This highly accurate machine-learned potential for Co opens exciting opportunities for further applications such as the dynamics of nanoparticles in catalytic reactions.

We predict a new family of two-dimensional (2D) material $MX{Y}_3$ monolayers ($M=\mathrm{V}$, Mo, W; $X=\mathrm{Al}$, Ga, In; $Y=\mathrm{S}$, Se, Te), and we perform a comprehensive investigation into their structural, electronic, and magnetic properties. First-principles calculations confirm the dynamical and thermodynamic stability of 21 materials among this family, underscoring their feasibility for experimental realization. The rich tapestry of magnetic phenomena presented in the $MX{Y}_3$ family ranges from ferromagnetism to various forms of antiferromagnetism, including the intriguing noncollinear states. We provide a detailed explanation for the origins of the various magnetic ground states. Specifically, V-based materials are ferromagnets with in-plane magnetocrystalline anisotropy, whereas Mo-based materials show a robust out-of-plane anisotropy ferromagnetic state. Most W-based materials display stripelike antiferromagnetism with significant orbital magnetic moments ($\sim 0.2{\mu }_{\mathrm{B}}$) and strong in-plane magnetic anisotropy, and they exhibit substantial electronic structure variations depending on the spin orientation. These antiferromagnetic W-based compounds are characterized by high critical temperatures, reaching up to 506 K for ${\mathrm{WAlS}}_3$. Interestingly, a significant anomalous Hall conductivity is identified in nonlinear antiferromagnetic $\mathrm{FeAl}{\mathrm{S}}_3$ and $\mathrm{FeGa}{\mathrm{S}}_3$, which is absent in conventional linear counterparts. This study suggests the great potential of $MX{Y}_3$ monolayers serving as a versatile platform for exploring fundamental physics and searching for new 2D magnetic materials.

It is now widely recognized that surface and interfacial defects exhibit distinct behavior compared to bulk defects in metal halide perovskites. However, the transition from bulk to surface behavior and the spatial extent of the surface's influence are not well understood. To address this, we conducted first-principles calculations on iodine vacancies and interstitial defects in methylammonium lead iodide and cesium lead iodide at various depths from the surface, enabling us to map out depth-dependent behavior. We find that the defect formation energy follows a saturating exponential curve as the defect moves away from the surface to the bulk. Using the calculated defect formation energies, we quantify the extent of the surface's influence by estimating the decay length associated with each defect. The difference between the surface and bulk defect formation energy is found to be as high as 1.12 eV for the negatively charged iodine vacancy in methylammonium lead iodide, leading to the enrichment of the surface with defects. Through analysis of defective structures, we find that the differences in the bulk and surface defect properties are a consequence of changes in Pb-Pb and Pb-I bond lengths. Finally, we determine how the defect transition levels change as a function of the layer index, which could contribute to increased nonradiative recombination. Our findings pave the way for a systematic treatment of nonradiative losses in perovskite solar cells that incorporate spatially dependent defect densities and transition levels.

We present a methodology using Differential Evolution Monte Carlo (DE-MC) to fit the parameters of an equation of motion to molecular dynamics (MD) trajectories of an $\frac{a}{2}\langle 110\rangle \left\{111\right\}$ edge dislocation in pure face-centered cubic (FCC) Ni, which is used as a model system. The motion of the edge dislocation under shear was observed using MD simulations with a classical effective potential, and the dislocation position was extracted. The parameters of interest were the effective mass, drag coefficient, and force experienced by the dislocation. Using DE-MC within a Bayesian framework, we estimated the joint posterior distribution of the parameters from the accepted samples produced by the DE-MC algorithm. The obtained distribution was then used to propagate the parameter uncertainties through the model, the equation of motion, which was used to predict the dislocation positions and velocities at the simulation timesteps as well as the uncertainty in the predictions. The mean fit was found to match the MD dislocation position data with a root mean square error (RMSE) of $0.2\mathrm{n}\mathrm{m}$. We demonstrate how parameter distributions determined using the proposed methodology can be applied to obtain a mobility law for the class of dislocations studied with quantified uncertainties. This work is part of a longer-term study aiming to develop a surrogate model for precipitation strengthening, specifically dislocation-precipitate interactions, in Ni-based superalloys with uncertainty quantification. Accordingly, we also discuss the limitations of the selected model within this context and the necessary model extensions to overcome them.

Electronic phase separation in lightly doped ${\mathrm{CaFe}}_3{\mathrm{O}}_5$ has been investigated through a variable temperature powder neutron diffraction study of ${\mathrm{CaFe}}_{2.99}{M}_{0.01}{\mathrm{O}}_5$ ($M=\mathrm{Co}$, Mn) samples. This reveals a complex series of proximate phase transitions. Lattice strains resulting from the onset of charge order (CO) drive formation of a competing charge averaged (CA) phase that emerges at $T_{\mathrm{CA}}=T_{\mathrm{CO}}=320$ K. The CA phase emerges as magnetically ordered but the long range spin ordering transition is limited by domain growth and so occurs at a slightly lower temperature ($T_{\mathrm{CA}\left(\mathrm{m}\right)}=301$ K for both samples). Magnetic ordering in the CO phase is not directly coupled to the other transitions, but is nearby in temperature with $T_{\mathrm{CO}\left(\mathrm{m}\right)}=290\left(1\right)$ and 292(1) K for $M=\mathrm{Co}$ and Mn samples. The remarkable coincidence of energy scales for the formation of two distinct electronic ground states with differing lattice strains and their long range spin orders thus results in electronic and magnetic phase separation through a series of thermally proximate phase transitions in lightly doped ${\mathrm{CaFe}}_3{\mathrm{O}}_5$.

Perovskite nitrides are starting to be explored for their promising properties distinct from their oxide counterparts. Here, through first-principles density functional computations, we study the intricate relationship between ferroelectricity and metallicity in the ferroelectric nitride ${\mathrm{LaWN}}_3$. We systematically assess the impact of electron and hole doping via the background charge method, revealing that both types of charge carriers diminish the propensity for ferroelectricity in ${\mathrm{LaWN}}_3$, although to remarkably different extents. Specifically, the introduction of electrons leads to centrosymmetry at a concentration value of nearly 0.2 electrons per formula unit. In contrast, the addition of holes does not result in centrosymmetry at reasonable doping values of up to 0.3 holes per formula unit. We present the underlying mechanisms behind these findings, noting that adding electrons fills the valence orbitals of both W and N atoms. This filling leads to a screening effect on the long-range interactions, between these atoms, thereby reducing the off-centering of W. On the other hand, hole doping does not significantly alter the W-N bonding nature, resulting in a more robust off-centering. Furthermore, we introduce explicit impurity atoms and analyze the influence of the different factors contributing to the change in polarization, namely, the size of the dopant, charge carriers introduced by the dopant, and changes in lattice constants. We discover that doped ${\mathrm{LaWN}}_3$ can be a promising polar metal, especially with acceptor dopants. Our study comprehensively shows the interplay between polarity and metallicity in this prototypical perovskite nitride.

Using the pulsed-laser-ablation technique, we successfully grew ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_{7-\delta }$ thin films with $c$-axis orientation perpendicular to the film surface. X-ray diffraction showed that the (00l) peaks can be well-indexed to the ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_{7-\delta }$ phase. Resistive measurements showed that the samples could be tuned from weak insulating to metallic behavior by adjusting the growth conditions. Surprisingly, no curves of $\rho -T$ in the temperature region of $2\sim 300\mathrm{K}$ showed anomalies corresponding to either the spin-density or charge-density wave orders, as seen in bulk samples. Hall effect measurements showed a linear field dependence on the dominant hole charge carriers, but the Hall coefficient $R_H={\rho }_{xy}/H$ exhibited strong temperature dependence. The magnetoresistance above about 50 K was positive but very weak, indicating a weakened or absent multiband effect. However, negative magnetoresistance was observed at low temperatures, which shows the delocalization effect of the magnetic field. Detailed analysis of the magnetoresistance suggested the delocalization effect at low temperatures is due to the Kondo-like effect rather than Anderson weak localization. Our transport results suggest that the electronic conduction is fulfilled by the $d_{x^2-y^2}$ orbital with holes as the dominant charge carriers, while the interaction through Hund's coupling with the localized $d_{z^2}$ orbital plays an important role in the charge dynamics.

Understanding the bottleneck to drive higher critical transition temperature $T_c$ plays a pivotal role in the underlying study of superconductors. Here we report a rare positive effect of direct substitution ${\mathrm{Li}}^{+}$ for ${\mathrm{Cu}}^{2+}$ cations on $T_c$ and intrinsic superconducting properties in ${\mathrm{Bi}}_{1.6}{\mathrm{Pb}}_{0.4}{\mathrm{Sr}}_2{\mathrm{Ca}}_2{\left({\mathrm{Cu}}_x{\mathrm{Li}}_{1-x}\right)}_3{\mathrm{O}}_{10+\delta }$ ($x=0–0.15$) or Li-doped Bi(Pb)-2223 compounds. Remarkably, we demonstrate that by employing long-time sintering accompanied by multiple intermediate calcining and pressing stages within our renovated solid-state reaction method, the optimal Li-doped samples achieve the well-established $T_c=111.1–113.8\mathrm{K}$. We evince the ${\mathrm{Li}}^{+}$ impurities diffuse sluggishly from a grain boundary into the high-$T_c$ phase during the extended synthesis process of Bi(Pb)-2223 materials. The presence of ${\mathrm{Li}}^{+}$ cations in the framework advances the overall copper oxidation state on the ${\mathrm{CuO}}_2$ planes, and as a result, the elevation of the hole concentration within the system enhances $T_c$. Furthermore, through analyzing the reliable excess conductivity data in the vicinity of the critical temperature based on the phenomenological Aslamazov-Larkin and Lawrence-Doniach models, we pronounce the improvement of the coherence length and the interlayer coupling strength between the ${\mathrm{CuO}}_2$ layers with respect to increasing Li-doped content. Our findings reinforce an insightful avenue to improve the critical temperature as well as intrinsic superconducting properties of the Bi(Pb)-2223 compounds by utilizing the appropriate synthesizing and doping processes.